1. Field of the Invention
The present invention relates to a head support arm with an improved datum system, an arm assembly for a disk drive device with the improved datum system, and a method for fabricating the head support arm and the arm assembly.
FIG. 1 shows a process for fabricating a prior head support arm. The head support arm 1 contains a carriage 2, a mount plate 3, a load beam 4 and a head/slider assembly 5. The carriage 2 is provided with a plurality of comb elements 2A, as well known in the art. The comb element 2 is provided with a swaging aperture 9, and the mount plate 3 is provided with a swaging boss 6. The swaging boss 6 and the swaging aperture 9 are fixed to each other as well known in the art. In the fabricating process, the load beam 4 is provided with a datum aperture 8 or a reference aperture used in an alignment. The boss 6 is used as a datum point in the alignment. In a first step, a center line of the mount plate 3 and a center line of the load beam 4 are aligned by using the datum boss 6 and the datum aperture 8. In a second step, both the mount plate 3 and the load beam 4 are coupled or fixed to each other by welding them at a plurality of spots 7. In a third step, a center line of a head/slider assembly 5 is aligned to the center line of the load beam 4 and fixed to the load beam 4. In a fourth step, the swaging boss 6 of the mount plate 3 is swaged to the swaging aperture 9 of the comb element 2A by using as datum points an aperture 10 into which a shaft is mounted and the datum aperture 8.
A similar structure to that shown in the FIG. 1 known in the art as a stackable arm (or unimount arm assembly, registered trademark of HTI Corp.) eliminates the mount plate 3, and welds the load beam 4 directly to a single arm 2 using the datum apertures 6, 8 and 10 for the alignment. A plurality of these arms are then arranged in parallel to create an arm assembly.
The alignment process uses the datum apertures 6, 8 and 10 to make the head supporting arm 1 in which all the center lines of the comb element 2A, the mount plate 3, the load beam 4 and the head/slider assembly 5 are aligned. Recently, the applicant of the present invention has proposed a head support arm in which an integrated wiring plate is mounted on the suspension load beam member, and a flexure is integrally formed on a front portion of the integrated wiring plate, and a head/slider assembly is mounted on the flexure. In this structure, it is additionally required to precisely align all the center lines of the arm member, the load beam member, the integrated wiring plate and the head/slider assembly. It is difficult to perform such precise alignment in the prior alignment process.